Thermal and Acoustic Performance of Al2O3, MgO ZrO2, and SiC Porous Media in a Flow-Stabilized Heterogeneous Combustor

A comparative analysis of performance of three different porous ceramic materials used as a flame-contained media within a flow-stabilized combustor is presented within this work. The experiments were performed at a constant air flow rate and variable methane flow rates. alpha-Al2O3, MgO ZrO2, and SiC highly porous ceramics were used as the porous media. All three porous media used in the study had equal dimensions and porosity and were located in the same fixed position within the combustion chamber. Characterization of the structure of porous media before experimentation was performed using multiple methods. During combustor operation, temperature profiles were collected along with optical and acoustic emissions and correlated with the composition of the gaseous methane/air mixtures. It was found that, while SiC enables the highest temperatures within the combustion chamber at higher equivalence ratios, the ionically conducting MgO ZrO2 porous media greatly expands the lean limit of combustor operation and is, thus, the preferred porous media material for lower equivalence ratio operation.